arch: mips: brcm: Add 7425 flash-edu support

Nand controller v5.0 and v6.0 have nand edu blocks that enable
dma nand flash transfers. This allows for faster read and write
access.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Acked-by: Paul Burton <paulburton@kernel.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200122213313.35820-3-kdasu.kdev@gmail.com

arch/mips/boot/dts/brcm/bcm7425.dtsi

@@ -403,8 +403,8 @@ nand: nand@41b800 {
 			compatible = "brcm,brcmnand-v5.0", "brcm,brcmnand";
 			#address-cells = <1>;
 			#size-cells = <0>;
-			reg-names = "nand";
-			reg = <0x41b800 0x400>;
+			reg-names = "nand", "flash-edu";
+			reg = <0x41b800 0x400>, <0x41bc00 0x24>;
 			interrupt-parent = <&hif_l2_intc>;
 			interrupts = <24>;
 			status = "disabled";